Electrical connection



R. J. MlLLER ELECTRICAL CONNECTION Filed May 31, 194:5

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En YMOND JM/LLEB ATTOgA/EX Patented 0t.", 1945 ELECTRICAL CONNECTION Raymond J. Miller, Detroit, Mich, asslgnor to Bendix Aviation Corporation, Detroit, Mich, a

corporation of Delaware Application May 31, 1943, Serial No. 489,219

3' Claims.

This invention relates to switches for electric circuits, and more particularly to switches tor circuits of high voltage.

Heretofore make-and-=break switches and connections for high voltage circuits have not proved entirely satisfactory, due to electric arcing incident to closin the circuit. Tins arcing frequently results in serious injury to the contact and/or contactor in that the cooperative parts are badly burned, and thus the emciency of the unit is destroyed. It is the aim of the instant invention to overcome this objection.

An object of this invention is to provide a make-ancl-brealz connection for an electric circuit wherein the possibility of arcing upon making and breaking the circuit is avoided.

Another object of the invention is to provide a make-ancl-breelt switch for an electric circuit so constructed and manipulated that actual physical contact between the cooperative elements is made in advance or" electrical contact.

Another object of the invention is to provide a make-and-break switch for an electric circuit so constructed that the flow of current through the switch may be efficiently controlled at all times.

Yet another object of the invention is to provide a make-and-break switch for an electric circuit wherein the contact and contactor of the switch cooperate with one another to constantly increase the how of current through the switch from substantially nil to maximum current.

A further object of the invention is to provide a make-and-break switch for an electric circuit wherein actual electrical contact between the cooperative elements of the switch may be regulated in successive steps.

Still a further object of the invention is to provide a make-anci-break switch for an electric circuit wherein the contact or contactor constitutes a variable resistance.

Other objects and advantages of the invention will appear from the following description taken in connection with the drawing forming a part of this specification, and in which,

Fig. 1 is a sectional view of a connection embodying the invention;

Fig. 2 is a side elevation of one type of switch embodying the invention;

Fig. 3 is a side elevation of another type of switch embodying the invention;

Fig. 4 is a side elevation of an electrical contact composed of a low-conductive material and a, high conductive material;

Fig. 5 is a side elevation of an electrical contact including a variable resistance;

Fig. 6 is a side elevation of an electrical contact composed of laminated. metal of decreasing resistance: and

Fig. 7 is a side elevation of an electrical contact composed of laminated metal with high resistance inserts.

Referring to the drawing for more specfic cleteils of the invention, it: represents generally an electrical connector including a shell or case it open at one end and closed at its other one as by a head M having a reduced portion to. The shell has therein a partition it dividing the shell into two compartments 2% and 2t; and the partition extends into the open end of the shell to provide independent openings for the coinpar-laments.

Corresponding terminals 2 and 26 are supported in the head it. The terminals include shanks 28 and Eli extended beyond the reduced portion l6 of the head, and binding or set screws 32 and t't mounted in the shanks serve to secure the respective leads of a cable 36 to the terminals,

- and a cap 3% slipped over the cable and fitted on the reduced portion iii of the heacl serves to house the terminals and the leads.

The terminals have stationary contacts to and t2 extended into the respective compartments 28 and 22. As shown, each of these contacts has a free end portion it or high or variable electrical resistance material terminating in a low electrical resistance material it adjacent the shanks.

A plu indicated generally at 48 has mounted therein contacts 59 and 52 connected to leads 5% and 56 in the conventional manner, and the contacts 50 and 52 have curved end portions 58 and St, adapted to slidably engage the stationary contacts to and 42.

In making the connection, the plug 48 is so manipulated as to place the free ends of the contacts 5t and 52 in the respective compartments 20 and 22 of the shell or case 52 in engagement with the portions cc of the stationary contacts so and it having high or variable electrical resistance. When the contacts till and 52 engage the extreme free ends of the stationary contacts to and t2, the voltage or flow of current is practically nil. However, as the plug it is forced to its seat on the shell, the contacts 59 l and 52 slide on the fixed contacts 4% and t2 and the flow of current gradually increases until the contacts 59 and 52 engage those portions 86 of the fixed contacts having low electrical resist- Led cal resistance, andcurved as indicated at H38. A

terminal Ho has mounted thereon a lever M2 adapted to be moved angularly by a conventional handle, not shown, and connected to the lever as by a spring lid is a contact N6 of low electrical resistance having slidable engagement with the stationary contact m2.

As the lever H2 is swung to engage the contact lit with the stationary contact )2, the contact iii; initially engages the free end of the portion ltd having high resistance, and hence admits of but little it any fiow of current through the connection. As the contact Ilt travels onthe curved face not of the portion H36 having high electrical resistance, the flow of current gradually increases until the contact H6 engages the portion i136 of the contact Hi2 where the maximum voltage or flow of current through the connection is attained.

In a further modification of the invention illustrated in Fig. 3, a bracket 20!] of suitable insulating material has mounted thereon a stationary contact 262 held against displacement by a terminal 2%. The contact has a portion 206 of low electrical resistance and a curved free end portion 206 of high or variable electrical resist- ,ance, decreasing gradually from its extreme free end to that portion having low resistance.

A terminal 2 I has pivoted thereon an arm 2l2 movable through an angle in any desirable manner, and the arm has a shoe 2 I l adapted to travel on the contact 202. The operation of this em bodiment of the invention is the same as that of the preceding embodiment.

Various types of contacts are illustrated in Figs. 4, 5, 6 and 7. In the embodiment shown in Fig. 4, a contact 300 has a portion 302 of low electrical resistance, and a portion 304 of high electrical resistance, and the portion 306 is preferably elongated.

In the embodiment illustrated in Fig. 5, a contact M10 has a portionMlZ of low electrical resistance, and a portion AM of variable electrical resistance. The variable resistance is preferably formed of sintered metal more or less porous at one end and relatively dense at its other end adjacent the portion 402 of low electrical resistance.

In the embodiment illustrated in Fig. 6, a contact 500 has 'a portion 502 of low electrical resistance, and a portion 506 of variable electrical resistance built up by laminated metals of varying electrical resistance.

In the embodiment of the invention illustrated in Fig. 7, a contact 600 includes a portion 602 of low electrical resistance and a portion 6M 01 aseaeea variable electrical resistance. The portion 505 is made of laminated metals comprising a plurality of low electrical resistance portions 8% interleafed with relatively small sections 6% of high electrical resistance. This provides means for gradually stepping up the voltage or flow of current.

While this invention has been described in connection with certain specific embodiments, the principle involved is susceptible of numerous other applications that will readily occur to per= .sons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

Having thus described the various features oi the invention, what I claim as new and desire to secure by Letters Patent is:

1. An electrical contact comprising a member having a section of low electrical resistance and a section of laminated metals each of different electrical resistance.

2. An electrical contact comprising a member having a short metallic section of low electrical resistance and a relatively long section of sinterecl metal porous at its free end and dense at its juncture with the section of low electrical resistance.

3. An electrical contact comprising a member having a short metallic section of low electrical resistance, and a section composed of a plurality of varying electrical resistance elements interleafed with metallic sections oi high electrical resistance.

4. An electrical connector comprising a shell open at one end and closed at its other end as by a head, a partition dividing the shell into two compartments, terminals mounted in the head, a removable cap on the head for enclosing the terminals, corresponding fixed contacts on the terminals extended into the compartments, each contact having a part adjacent the terminal of low electrical resistance and a free end part of high electrical resistance, and a plug having contacts adapted to be inserted in the compart- 1 ments in sliding engagement with the stationary contacts.

5. An electrical connection comprising a shell having compartments therein, fixed variable contacts in the compartments, and a plug having contacts adapted to slidably engage the variable contacts.

6. An electrical connection comprising a shell having individual compartments, a fixed variable contact in each or the compartments, and a plug having contacts adapted to slidably engage the fixed contacts.

7. An electrical connection comprising a shell having an open end, a partition in the shell extending into the open end providing individual compartments within the shell, a fixed contact in each compartment varying in density from its free end inwardly, and a plug having contacts adapted to be inserted in the compartments in sliding engagement with the fixed contacts.

- RAYMOND J. 

